Conventional connectors for use in coupling electric/electronic circuit boards with external units for transferring signals between the boards and units are formed of terminal securing portions and housing portions which are integral with the terminal securing portions and made of insulating materials such as plastics.
In order to prevent dissipation of signals or electromagnetic waves from naked conducting portions of the connectors and to prevent resultant noise problems caused by the leakage of the electromagnetic waves, these connectors are subjected to surface treatment such as electroplating or metal-vapor deposition.
However, if a whole connector is surface treated, its terminals, and hence the circuit on the board, can be short-circuited or electrically connected by a metal film formed in such surface treatment, causing serious disadvantages.
In order to prevent such short-circuiting of the circuit, those portions that must not be surface-treated are conventionally masked with masking tape prior to the surface treatment.
This conventional method, however, requires a tedious process of masking the surface in conformity with fine configurations of the connector, which lowers manufacturing efficiency and increases manufacturing cost.